Craig and Tom, working together, can clean the house in 8 hrs, working alone, Tom takes four times as long as Craig, How long does it take Craig to clean the house?

Let x = Craig's time

Let y = Tom's time

Create a system of equations to solve this problem.

8 = x + y

y = 4x

Substitute 4x into the y variable in the first equation.

8 = x + 4x. Combine like terms

8 = 5x. Divide each side by 5.

1.6 = x

Craig takes 1.6 hours to clean the house